The present invention is directed to a wound dressing system having an integral wetting system for maintaining the wound in a moist condition.
It has been found that moist wounds often heal faster. Numerous types of wound dressings have been developed that are designed to maintain a favorable moist environment. For example, an occlusive dressing is designed to keep a wound from being exposed to air, thus reducing evaporation. Many dressings, such as those disclosed in U.S. Pat. Nos. 6,153,214 (Horsier) and 5,695,777 (Donovan et al.) incorporate a water-swellable fiber or intermediate hydrogel layer to promote localized areas containing moisture.
However, these dressings are limited in the kind of fluid used to form the fiber or layer, and, if fluid must be added to the dressing, then the dressings must be constantly tended. Further, pouring water, antibiotic solution, or some other solution on the dressing results in variable wetting and dry spots, both of which may adversely affect wound healing and increase the risk of wound infection and desiccation.
To address uniform wetting, U.S. Pat. No. 6,162,960 (Klein) discloses a compression sponge for dressing a wound having at least one uniform bibulous layer to wick or absorb and retain liquid. The uniform liquid distribution throughout the entire layer provides uniform pressure distribution of any externally applied pressure on the dressing. This type of dressing also requires constant tending, in practice, because it develops dry spots. This type of dressing also is inefficient and ineffective for applying many solutions containing certain therapeutic substances.
A dressing similar to that described in the Klein patent is the Acticoat(copyright) Burn Dressing (Westaim Biomedical, Exeter, N.H., U.S.A.). The Acticoat(copyright) Burn Dressing includes silver-coated outer layers to protect against infection while the inner core maintains moisture in the dressing. This dressing requires that sterile water be poured on it regularly to provide for continued moisture to be present within the dressing""s inner core material. Usually, the Acticoat(copyright) Burn Dressing requires water to be wetted down every four to six hours.
The inventors have found that failing to keep the entire wound area moist or wet leads to increased risk of infection and/or dessication of the wound area. To date, no satisfactory dressing has been developed for difficult wounds, such as deep burns or chronic wounds including decubitus ulcers, venous stasis sores, radiation ulcers, pressure sores, ischemic ulcers or diabetic ulcers. Treatment of these wounds remains a very long and expensive process requiring staff to continually and/or frequently monitor the moisture level of a dressing.
Notwithstanding the usefulness of the above-described methods, a need still exists for a dressing that maintains a moist environment with little monitoring by the medical staff required.
A wound dressing system in accordance with the present invention preferably includes a dressing and an irrigation system. The dressing preferably includes a first layer (or wound-contacting layer) and a second or outer layer, which preferably provides a moisture barrier. The irrigation system preferably is interposed between the first layer and the second layer of the dressing. A further embodiment of the invention is a complete system that adds an automated pump to supply the irrigation system.
The absorptive wound dressing system of the invention in its broader aspects preferably includes a laminar structure of three or more layers as follows: a) a porous medical grade polymer material layer that is placed in direct contact with the wound and which is characterized as being wound friendly; b) an intermediate layer including an irrigation system, typically formed of a matrix or assembly of conduits; and c) an outer vapor impermeable layer for maintaining the moisture content within the dressing. Optionally, the first layer may be able to wick or otherwise transfer exudate away from the wound. Also, the outer layer may be of a larger surface area than the other layers so as to include a peripheral skin-contacting adhesive on the underside thereof surrounding the wound area and facilitating contact and covering of the wound.
According to one form of the invention, a wound dressing system including a dressing having a first layer, the first layer including a material suitable for contacting a wound, and a second layer connected to the first layer, the second layer including a backing layer; and an irrigation system in communication with the first layer of the dressing, the irrigation system having at least one conduit.
According to one form of the invention, a wound dressing system including a first layer including material suitable for contacting a wound, a second layer including a backing material attached to the first layer, an irrigation system in communication with the first layer, and a means for providing pressure differential connected to the irrigation system.
According to one form of the invention, a wound dressing including a means for covering a wound, a means for preventing seepage from the dressing, and a means for maintaining wetness within the covering means.
According to one form of the invention, a system including a dressing having a first layer, the first layer including a material suitable for contacting a wound, and a second layer connected to the first layer, the second layer including a backing layer; and an irrigation system in communication with the dressing, the irrigation system having at least one connector, at least one external conduit connected to the connector, the external conduit having a passageway in communication with the connecter, and at least one internal conduit, the internal conduit having a passageway in communication with the passageway of the at least one external conduit and a plurality of holes spaced along the length of the internal conduit, the plurality of holes allowing communication between the passageway of the internal conduit with the first layer of the dressing, the internal conduit forming a pattern within the dressing.
A dressing system in accordance with the present invention may be used for protection of wounds, for infection control, for control of conditions (such as water content, osmolarity, pH, salt concentration, oxygen concentration) in wounds, for thermal regulation, for delivery of bioactive substances (such as nutrients; antibiotics, vasodilatants, vasoconstrictors, steroids and other bioactive substances; growth factors, hormones, enzymes, stimulants and other biomolecules; sulfamylon; silver) into wounds, for removal of harmful substances from wounds, and for protection and support of the human cells proliferating in wounds.
The primary function of the dressing system of the present invention is to occlude the wound, to control its environment, and to promote healing by maintaining the wound area at a certain pre-determined level of moisture content. The dressing system also uniformly distributes moisture or fluid through the wound area, and prevents or reduces the size and number of dry spots covering the wound.
These dressings promote formation of granular tissue in the wound bed, facilitate migration of epidermal cells, and help to control infections. This leads to faster closure of the wound, less pain, and less scarring.
An objective of the invention is to keep the wound and surrounding area (such as bedding and the patient""s clothes) clean thus reducing time changing dressings and cleaning the surrounding area.
A further objective of the invention is to reduce the personnel time needed/required to manually keep dressings wet by regularly and frequently checking to see if the dressing is suitably wet and when it is not pouring additional fluid onto the dressing.
A further objective of the invention is to automate the application of fluid to dressings thus decreasing the manpower needed to monitor dressings for wetness.
The accompanying drawings show illustrative embodiments of the invention from which these and other of the objectives, novel features and advantages will be readily apparent. Given the following enabling description of the drawings, the apparatus should become evident to a person of ordinary skill in the art.